# Math Help - Difficult Substution Problem

1. ## Difficult Substution Problem

x[0,1] f(x)=sinx/1+x^2

isn't 1+x^2 arctan?
I wasn't sure how to approach this problem, I know sin/cos = tan, so would i use 1/2 x dx/1+x^2? I have no clue haha. Help please.

2. As written, the integrand is as follows:

$\frac{\sin(x)}{1}\, +\, x^2$

I have a feeling you mean one of the following...?

$\mbox{a) }\,\frac{\sin(x)}{1\, +\, x^2}$

$\mbox{b) }\,\sin\left(\frac{x}{1\, +\, x^2}\right)$

Please confirm or correct. Thank you!

3. Originally Posted by stapel
As written, the integrand is as follows:

$\frac{\sin(x)}{1}\, +\, x^2$

I have a feeling you mean one of the following...?

$\mbox{a) }\,\frac{\sin(x)}{1\, +\, x^2}$

$\mbox{b) }\,\sin\left(\frac{x}{1\, +\, x^2}\right)$

Please confirm or correct. Thank you!

I meant a

4. so I guess no one understands this.